body {
    margin: 0;
    background-color: #eee;
}
.wrapper {
    padding-top: 100px;
    text-align: center;
}
button {
    padding: 10px 20px;
    font-size: 32px;
    background-color: #ddd;
    color: #777;
    border: 4px solid #777;
    outline: none;
    -webkit-transition: all .15s ease-out;
    -moz-transition: all .15s ease-out;
    -ms-transition: all .15s ease-out;
    transition: all .15s ease-out;
}
button:hover {
    color: #444;
    border-color: #444;
    cursor: pointer;
}
.intro p {
    font-size: 20px;
    color: #666;
}
.intro p.division {
    font-size: 28px;
    font-weight: 700;
    color: #aaa;
}
@media only screen and (max-width: 640px) {
    .intro p:not(:first-child),
    .qrcode {
        display: none;
    }
}